Distinctive Performance of Terahertz Photodetection Driven by Charge‐Density‐Wave Order in CVD‐Grown Tantalum Diselenide

Abstract

The quantum behavior of carriers in solid is the foundation of modern electronic and optoelectronic technology, but it is still facing huge challenges within inherited single‐particle quantum processes working at the millimeter wave/terahertz (THz) band. Here, a straightforward strategy for the direct detection of millimeter wave/THz photons in a sub‐wavelength metal‐TaSe2‐metal structure under strong interaction with a localized field of surface plasmon is proposed. By breaking the inversion symmetry under the perturbations of electric field and atomic reconstruction from van der Waals integration, the nonequilibrium electronic states under a radiant field can be manipulated in a collective fashion, leading to a large photocurrent responsivity over 40 A W−1 and noise equivalent power less than 1 pW Hz−1/2 even at room temperature. A more than 40‐fold enhancement in responsivity is achieved when transitioning from the normal phase to the CDW phase. The findings shed fresh light on the understanding of the delicate balance in the charge‐ordered phase, and facilitate the exploitation of a correlated electron system for optoelectronic applications in fields of security, remote sensing, and imaging.

2D Material Based Synaptic Devices for Neuromorphic Computing

“…[ 153–155 ] CVD method features its versatility in material synthesis, covering metals, semiconductors, insulators, superconductors, charge‐density‐wave (CDW) materials and magnetic materials. [ 157–160 ] Furthermore, with multistep synthesis, various vertical and lateral heterostructures can be obtained, such as vertical MoS 2 /h‐BN heterostructures [ 161 ] and planar triangular WS 2 –WSe 2 –WS 2 –WSe 2 superlattices. [ 155 ] Zhou et al.…”

Recent Advances in New Materials for 6G Communications

“…The frequency‐dependent conductance and optical pumping experiments of 2H‐TaSe 2 show that the strong resonance of the collective response is related to the CDW ground state in the frequency range of millimeter and THz waves, which makes it a superior system for realizing high‐sensitivity optoelectronic devices with a photon energy significantly lower than that of a single particle gap. [ 56,57 ] Room temperature THz detection mediated by CDW excitation was demonstrated for the first time in the prototype device of a metal–TaSe 2 –metal structure, realizing the high‐efficiency conversion from the low‐energy electromagnetic radiation to the electrical signal. [ 57 ] Using the local surface plasmon‐induced electric field, the coupling between the normal state and the CDW condensed state provided a response rate of up to 40 A W −1 and the low NEP was reduced to 1 pW Hz −1/2 , which enabled a new way of realizing a large area, fast imaging, and remote sensing in the THz band.…”

“…[ 56,57 ] Room temperature THz detection mediated by CDW excitation was demonstrated for the first time in the prototype device of a metal–TaSe 2 –metal structure, realizing the high‐efficiency conversion from the low‐energy electromagnetic radiation to the electrical signal. [ 57 ] Using the local surface plasmon‐induced electric field, the coupling between the normal state and the CDW condensed state provided a response rate of up to 40 A W −1 and the low NEP was reduced to 1 pW Hz −1/2 , which enabled a new way of realizing a large area, fast imaging, and remote sensing in the THz band.…”

Recent Progress and Future Opportunities for Hot Carrier Photodetectors: From Ultraviolet to Infrared Bands

“…[20,21] Figure 1 shows that hot carrier photodetectors can work in a long spectral range from the ultraviolet (UV), visible, infrared (IR) to terahertz (THz) bands as shown in the electromagnetic spectrum. [13,[21][22][23][24][25][26][27] For example, hot electrons are utilized in the Sn-SiO 2 -Si system with a barrier height (Φ b ) of ≈3.8 eV to implement solar-blind UV detection. [21] In addition, the plasmonic stripe antenna in the gold-aluminum oxide-gold (Au-Al 2 O 3 -Au) structure (Φ b = 2.6 eV) and the plasmonic crystals of gold-titanium dioxide-Indium tin oxide (Au-TiO 2 -ITO, Φ b = 0.68 eV) are reported to improve the photoresponse across the visible and near-infrared bands by exciting surface plasmon resonances.…”